My little boy is getting so big. The time is flying by so quickly that it leaves me breathless if I stop to think about it. His 18-month check-up was yesterday afternoon, so I decided to bring him into my office afterward so he could meet my co-workers. Our adventure reminded me that being in a different environment is sometimes the best way to learn new things about your child.

When I arrived at school to pick Mason up he was curled on his cot, just waking up from his nap. He was playing quietly with a shoe and my heart melted when he looked up, saw that I was there for him, jumped up, and ran to me. He didn’t make a peep and I was so proud of him for not waking up any of his classmates who were still sleeping.

Discovery 1: He will follow specific routines, such as lying on a cot completely silent until nap ime is over, to meet expectations.

We schlepped to the doc’s office, and Mason sat in a chair in the waiting room eating his organic graham crackers and watching cartoons until the nurse called us back (left.)

Discovery 2: Without a doubt, he can follow directions. He’ll sit still in a chair for up to 10 minutes–even when other kids are running around right in front of him.

The new pediatrician that we saw was awesome–thorough but laid-back, upbeat and reassuring. (It was the same practice that we normally go to, but our usual pediatrician wasn’t there today.) I think we’re going to switch to her. I left the office feeling happy, not anxious like I normally do. Mason seemed much happier throughout the appointment, too, despite the big shot he got at the end of his appointment.

Discovery 3: Mason’s sensitive to situations and emotions, just like I am. He clearly picked up on my discomfort with the last pediatrician–and my ease with this one.

The only downer was when the nurse told me Mason hadn’t gained an ounce–literally, not one ounce–since our visit in January. I swear I thought the scale was broken. The doctor thinks his lack of weight gain is probably due to the terrible stomach bug that hit him last month. (The vomit-fest struck the afternoon I kept him home from school because he had a bad cough…I spared you guys the gruesome details.) He was so sick we almost had to go to the ER, so she’s guessing he lost weight during that time but had managed to gain it back before his check-up. Of course now we’re back to square one with another weigh-in in a few weeks to confirm that he’s back on track.

Seriously? Seriously?

What are the odds of Mason finally reaching his weight goals only to get hit with the stomach virus from h-ll just weeks later? The doc said she was very optimistic everything is still fine (“He’s clearly thriving, look at him,” she said). But still.

After the appointment, we went back uptown to my office, and it was clear he immediately felt comfortable there. He walked around like he owned the place. He blew kisses and played Peek-a-Boo, performing for his audience of admirers. Taryn and Erica played ball with him. Tracy, our beauty director, let him play with the colorful bottles and jars on her desk. Jessie followed him snapping pics for Twitter (right).

Discovery 4: In a positive environment kids will warm up quickly, even if they’re in an unfamiliar place surrounded by people they’ve never met before.

Mason had so much fun that he let out a blood-curdling scream when I told him it was time to leave. It was deafening and mortifying–sorry Jessica, Kourtney, Taryn, and Tracy. Luckily I work in a place where everyone loves children. I don’t think anyone will hold a grudge.

On our way out we stopped by Katherine’s office, a friend who works at another magazine owned by the same company as Parents. Mason turned on the charm with her until it was time to go and she needed to put the iPhone he was playing with back in her bag. I forgot to warn her about the iPhone. The sudden loss of his favorite gadget in the world led to a spectacularly dramatic temper tantrum. Screaming, on the ground, in her office. She’s expecting twins in May, and I told her that I was sure little girls didn’t make such scenes. (If you’re a mom of a little girl you can stop laughing now….) But she handled it like a champ, and I think she still likes him. I think.

Discovery 5: Hide every iPhone the minute you walk into a room–never underestimate a happy toddler’s ability to have an immediate breakdown at the worst possible place and time.

After Mason went to bed last night, I texted Chris and told him I was “absolutely overwhelmed with love” for Mason. I think changing up our routine, if only for a day, was a fun way to bond.

you certainly have a sweet one there! nice day out of the routine for you. sometimes i think they are as important as the routine itself. happy weight gain. you sound more comfortable with it this time around.